Electronic shutter for frame-transfer EMCCD using anti-blooming channel to bleed off charges

To resolve the issues of the image blurring of high-speed moving objects and the imaging saturation of high brightness objects and missing detail, an electronic shutter method for frame-transfer EMCCD using anti-blooming channel to bleed off charges and external time frequency control was proposed. Through bleeding off the charges in light sensitive area into the anti-blooming channel which adjacent to the storage area, an adjustable electronic shutter among 1/25 s and 1/1 000 s was realized. And at the same time, the standard video signal was output continuously. The relationship between the illumination intensity and the maximum bleeding-off current of the anti-blooming drain was formulated. The smear effect induced by the short exposure time (shutter time) was corrected online through writing the correction algorithm into the FGPA chip of the EMCCD readout circuit. A prototype system using frame-transfer EMCCD with anti-blooming channel was built up to conduct imaging experiments. The results verify that this electronic shutter can effectively decrease the image blurring of rotating objects and facilitate high dynamic range imaging in the nighttime.